Hello, Would it be possible for me to extend my stay or change my status from tourist visa?

I will be traveling to China on a tourist visa but if my girlfriend decide to marry me in China would I be able to extend my stay or change my status from being a tourist to permenant residence? also what documents should I bring with me since I was divorced last year in USA. I lived in California for 30years, Texas for one year and now I lived in Washington state for 6 months. I was unable to contact the chinese Embassy here. I left them an email but they did not reply to me. Do you have the contact information and website?